Silver vanadium oxide (SVO), Ag2V4O11, shows high gravimetric and volumetric energy densities. When SVO is used as a positive electrode in batteries in implantable medical devices, it performs most of the time at low power and occasionally delivers one or more high power pulses. SVO provides an electrode potential curve with multiple plateaus, which allows one to accurately predict the lifetime of the battery.
The synthesis methods of SVO are divided broadly into two categories—decomposition and combination reaction methods. The former method uses decomposable silver compounds accompanied by the evolution of toxic NOx gas during heat-treatment. In the combination reaction method, silver oxide Ag2O reacts at high temperature with vanadium pentoxide V2O5 in 1:2 molar ratio without liberating any gaseous products. The combination reaction leads to a well-crystallized SVO with higher surface area, when compared with the material synthesized using the decomposition reaction.
While the theoretical discharge capacity characteristics of SVO are quite high, much lower utilization of SVO is typically attained, especially at high discharge rates due to high particle-to-particle resistance and electrical resistivity of SVO. The internal cell resistance increases with progressing discharge, resulting in a poor power capability in Lithium/SVO cells. While attempts have been made to improve the electrochemical performance of the SVO electrodes by optimizing the synthesis process and by introduction of substitution atoms, a need exists enhanced discharge capacity and rate capability.